(1) Field of the Invention
The present invention generally relates to disk ejection mechanism of a disk drive, and more particularly to a disk ejection mechanism of a disk drive, installed in a casing of a personal computer, wherein a disk tray is ejected when an eject operation is performed by an operator on the personal computer.
(2) Description of the Related Art
FIG. 1 shows a conventional CD-ROM disk drive. This CD-ROM disk drive is a built-in type that is installed in a casing of a notebook-size personal computer for use and operation. A CD-ROM (Compact Disk-Read-Only Memory) is a type of optical disk which is capable of storing large amounts of information. The CD-ROM is accessed by an optical pickup of the CD-ROM disk drive in order to reproduce information on the CD-ROM.
In the above optical disk drive, a tray 1 on which an optical disk (not shown) is held is movably supported. The tray 1 is movable in forward and rearward directions (indicated by arrows A and B in FIG. 1) of the optical disk drive. The movement of the tray 1 is actuated by a manual operation.
The tray 1 includes an opening 1a. A turn table 2 is provided under the opening 1a of the tray 1, and the optical disk on the tray 1 is held by the turn table 2. Since the turn table 2 is rotated by a spindle motor (not shown in FIG. 1), the optical disk on the tray 1 is rotated by the turn table 2. An optical pickup 3 which optically reads out information on the optical disk is provided under the opening 1a of the tray 1.
A disk ejection mechanism included in the above optical disk drive performs an ejecting action of the tray 1 when a pushdown eject button 4 is pushed, so that the optical disk on the tray 1 can be taken out by the operator. The eject button 4 is provided on, for example, a front bezel in front of the tray 1. When the tray 1 is placed at its inserted position, a lock lever 5, which is supported on the bottom of the tray 1, is connected with a pin 6 provided on a chassis 10. The tray 1 at the inserted position is locked by the lock lever 5 connected with the pin 6. The pin 6 is fixed on the chassis 10.
The lock lever 5 has an L-shaped cross-section. The lock lever 5 has a hook portion 5a at one end, and a contact portion 5b at the other end. When the tray 1 is placed at the inserted position, the hook portion 5a of the lock lever 5 is connected with the pin 6, and the contact portion 5b of the lock lever 5 is brought into contact with a rear surface of the eject button 4.
The lock lever 5 further includes a supporting shaft 5c. The lock lever 5 is rotatably supported on the supporting shaft 5c such that the lock lever 5 is rotatable around the supporting shaft 5c in a horizontal plane. A coil spring 7 is connected to an intermediate portion of the lock lever 5, and an actuating force to rotate the lock lever 5 in a clockwise direction around the supporting shaft 5c is exerted by the coil spring 7 such that the hook portion 5a is forced toward the pin 6.
A tray pushing member which pushes the tray 1 in the forward direction "A" is provided at a rear portion of the tray 1. When ejecting the tray 1 from the chassis 10, the tray pushing member pushes the tray 1 so that the tray 1 is moved from the inserted position in the forward direction "A" by a predetermined distance. This facilitates the operator to further pull out the tray 1 from the chassis 10. In this tray pushing member, a pair of projections 1c extending downward from the bottom of the tray 1 are provided. A pushing lever 8 having an opening is fixed on the chassis 10. The tray 1 is slidably supported by the projections 1c connected with the opening of the pushing lever 8. A coil spring 9 is connected to the chassis 10 and the tray 1, and an actuating force to push the tray 1 in the forward direction "A" is exerted by the coil spring 9 on the tray 1.
When the tray 1 is inserted into the optical disk drive, an end 8a of the pushing lever 8 is brought into contact with a rear inside wall 10a of the chassis 10. When the tray 1 is at the inserted position, the coil spring 9 is stretched by a length that is the same as a length of an extending portion of the pushing lever 8 projecting from the rear end of the tray 1.
FIG. 2 shows the conventional CD-ROM disk drive when the eject button 4 is pushed. As shown in FIG. 2, the lock lever 5 is rotated counterclockwise around the supporting shaft 5c when the eject button 4 is pushed down. The hook portion 5a of the lock lever 5 is released from the pin 6 on the chassis 10.
FIG. 3 shows the conventional CD-ROM disk drive when the tray 1 is ejected from the chassis 10. When the tray 1 is at the position shown in FIG. 3, the front bezel 1b in front of the tray 1 is distant from the front end of the chassis 10 by a predetermined length "L". This facilitates the operator to further pull out the tray 1 from the chassis 10, so that the optical disk on the tray 1 can be taken out by the operator. The operator can change the optical disk by a new optical disk after the tray 1 is further pulled out from the chassis 10. The position to which the tray 1 is further pulled out so as to make the optical disk on the tray 1 fully exposed, is referred to as a disk-change position.
Further, in the conventional CD-ROM disk drive, it is necessary that the eject button 4 has a relatively large height on the front bezel 1b, or it has a relatively large size enough to allow for an easier manipulation of the eject button 4.
However, in the case of the conventional optical disk drive, the eject button 4 is provided on the front surface or the side surface of the notebook-size personal computer. Therefore, it is possible that the operator on the personal computer erroneously touch the eject button 4 when the optical disk is being accessed by the CD-ROM disk drive 11. Since the pushdown eject button 4 has a short stroke that is needed to actuate the tray for the ejecting action, it is likely that the ejecting action of the tray 1 is actuated in such a case even when a pressing force acting on the push button 4 is slight.
If the eject button 4 is inadvertently pushed down when the optical disk is being accessed by the pickup 3, the tray 1 is moved in the forward direction A and the unlocking of the lock lever 5 is actuated. There is a problem that a reading action of the pickup 3 is interrupted by the movement of the tray 1.
Further, it is possible that the eject button 4 be inadvertently pushed down by a person when the personal computer is carried by the person. In such a case, the tray 1 is moved in the forward direction A so that the tray 1 outwardly projects from the chassis 10. The tray 1 outwardly projecting from the chassis 10 is likely to be damaged or deformed by an external force by accident.
One method for resolving the above-mentioned problems is to provide a locking mechanism which is installed in a disk drive and locks the eject button 4 when the disk drive is operated or carried. The locking mechanism installed in the disk drive can lock the eject button 4 when the disk drive is operated or carried, in order to prevent the disk tray from being erroneously ejected. However, the disk drive in which the locking mechanism is installed must have a complicated structure. In addition, it is necessary for the operator to perform an unlocking operation of the locking mechanism to unlock the eject button 4 before the eject button 4 is pushed down to eject the disk from the disk drive. The locking and unlocking of the eject button 4 is not useful for the operator and become annoying operations for the operator.